Convertible bulk hand truck

ABSTRACT

A convertible bulk hand truck is described which is capable of being adjustably positioned by virtue of a unique foldable adjustable linkage between folded and unfolded positions to define either a two wheeled dolly device or a four wheeled platform cart. The hand truck is lightweight, yet strong and rigid for dependable performance in hard, everyday service, has excellent load stability and is capable of transporting stacked products around manufacturing and sales points with maximum ease.

United States Patent [1 1 Doheny [451 Jan. 15, 1974 CONVERTIBLE BULKHAND TRUCK [75] Inventor: William Michael Doheny, Atlanta,

[73] Assignee: The Coca-Cola Company, Atlanta,

22 Filed: Aug. 28, 1972 21 Appl. No.: 284,329

[52] U.S. Cl. 280/47.l8, 280/4727 [51] Int. Cl B62b 3/04 [58] Field ofSearch 280/47.18, 47.2, 280/4727 [56] References Cited FOREIGN PATENTSOR APPLICATIONS 686,l48 l/l967 Belgium 280/47.l8 956,468 8/1949 France280/472 1,500,291 9/1967 France 280/47. 1 8

Primary Examiner-David Schonberg Assistant Examiner-John A. PekarAttorney-William Dexter Brooks [57] ABSTRACT A convertible bulk handtruck is described which is capable of being adjustably positioned byvirtue of a unique foldable adjustable linkage between folded andunfolded positions to define either a two wheeled dolly device or a fourwheeled platform cart. The hand truck is lightweight, yet strong andrigid for dependable performance in hard, everyday service, hasexcellent load stability and is capable of transporting stacked productsaround manufacturing and sales points with maximum case.

10 Claims, 9 Drawing Figures PATENTEUJAN 1 5 [924' SHEET 1 (If aPATENTEUJAH I 51974 SHEET 2 OF a llln...

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All] mnll ll CONVERTIBLE BULK HAND TRUCK BACKGROUND OF INVENTION Thepresent invention relates to a convertible bulk hand truck capable ofbeing adjustably positioned between folded and unfolded positions todefine either a two wheeled dolly device or a four wheeled platformcart.

The transportation of cases of bottled beverages, such as milk, softdrinks, beer and wine and the like by a bottler from a bottling plant toa route distribution point has always been 'a time consuming andexpensive operation. It has heretofore been practiced where these caseswere to be delivered, that two basic types of manually operated wheeledtransporting devices be employed for handling the cases.

The first and most common type of wheeled device consists of anelongate, normally upwardly and rearwardly projecting materialsupporting frames with handles at its upper end, a forwardly projectingmaterial engaging and supporting toe plate at its lower end and a pairof laterally spaced support wheels mounted at the lower end of the frameto occur rearwardly thereof. This type of device has become commonlyknown as a dolly device.

Dolly devices, such as described above are made in many different andspecial designs for special uses. For example, specially designed dollydevices with short toe plates, are provided for handling goods in smallpackages or containers. Such specially designed dolly devices are notsuitable for handling large cartons or sacked goods, such as coal orpotatoes. Accordingly, specially designed dolly devices with larger orlonger toe plates are provided for handling these large cartons andsacked goods.

In addition to the above example, specially designed dolly devices areprovided for handling barrels or drums, soft drink cases, appliances andmany other goods and materials which present special handling problems.

As a result of the above, a great number of shops, warehouses, storesand common carriers, must purchase, maintain and use a wide variety ofdolly devices. The necessity and/or desirability of having severalavailable types or styles of dolly devices is expensive, complicated andtroublesome.

The other or second type of wheeled device that the art has developedand which finds wide use throughout industry includes an elongatehorizontally disposed frame with an upwardly projecting handle at oneend, a pair of support wheels, on fixed axles, at one end of the frameand a pair of caster type wheels at the other end of the frame. Thisfour wheeled type of truck is commonly referred to as a flat bedplatform truck and is widely used to carry or transport goods which aretoo bulky or of such size and shape that they cannot be advantageouslytransported on a two wheeled dolly device.

The latter, second type of truckis widely used in shops, warehouses andstores but is infrequently used by truckers or common carriers, in spiteof the frequent need for such a truck. This is primarily due to the factthat such trucks are awkward and difficult to handle, as for instance,they are difficult to load and unload from trucks and similar vehicles.Furthermore, such trucks occupy considerable space and there is apractical limit as to the number of special pieces of work handlingequipment a trucker or common carrier can be equipped with.

Under practical circumstances, both types of manually operated wheeledtransporting devices are generally employed. This results in aconsiderable expense because of increased time requirements for deliveryroutes and/or increased equipment expenditures.

These increased expenditures have become disastrous in recent years,since there has been a growing trend in the industry to shiftcompensation for the delivery salesman function from a base pluscommission to an hourly basis. One result of this has been the equationof time and money in terms of route delivery. Thus, by decreasing thetime requirement of route delivery, substantial monetary savings can beachieved. With the advent of preselling delivery, delivery routes nowdeliver more cases and consequently pick up more empty containers. Sincethis handling requirement is exponentially proportional to the number ofcases delivered, new delivery devices are needed to reduce deliveryefficiencies, thereby resulting in additional expenditures of capitaland labor.

Accordingly, there has arisen a need in the industry for the productionof a convertible bulk hand truck, preferably of simple construction,that is capable of being adjustably positioned between folded andunfolded position to define either a two wheeled dolly device or a fourwheeled platform cart. The bulk hand truck should be capable of beingadjustably positioned quickly at all times between the folded andunfolded positions and accomodate packages of different types and sizesin a stacked arrangement at manufacturing and sales points.

OBJECTS OF INVENTION An object of the present invention 'is to provide amanually operated, wheeled material handling truck which is convertiblefrom a two wheeled dolly device" to a four wheeled platform truck."

Another object of the present invention is to provide a convertible handtruck of the character referred to herein having an elongate frame witha toe plate and a pair of primary support wheels at one end and asecondary handle having casters at the other end whereby saidconstruction is serviceable as a two wheeled dolly device in its uprightposition.

Another object of the present invention is to provide a convertible handtruck of the character referred to herein wherein a pair of secondary,caster type, support wheels are provided at the end portion of the frameremote from the primary support wheels, which secondary support wheelscooperate with the primary wheels and serve to support the frame in ahorizontal position when it is employed as a two wheeled dolly deviceand is in a down or horizontal position and which serve as supportingand turning wheels when the device is used as a platform cart.

Still another object of the present invention is to provide a novelgravity operated pivot linkage between the secondary handle and frame toenable a user to convert the hand truck from a standard upright twowheeled application to four wheeled platform application in seconds.

Another object of the present invention is to provide a hand truck ofthe character referred to herein having a novel spring activated lockingmechanism for securing a secondary handle locking bar to the rear of thehand truck bed during the upright application and having a footreleasable lever associated with the locking mechanism so that uponbeing depressed, the secondary handle locking bar is pushed free fromthe rear of the hand truck readying the hand truck for conversion to theplatform application.

A further object of the present invention is to provide a hand truck ofthe character referred to wherein the secondary caster support wheelsare provided at the end of the secondary handle so as not to interfereor otherwise obstruct the user while the truck is in the uprightposition.

A further object of the present invention is to provide a utility handtruck of the character referred to having a novel, rigid, durable andcompact frame construction; a truck which is easy and economical tomanufacture and a truck which is highly effective, dependable and easyto operate.

These, other, and further objects, important features, and advantages ofthe present invention to which attention has not been specificallydirected hereinabove, will be better understood and appreciated by thoseskilled in the art from the following detailed description of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWING The present invention will now bedescribed, by way of example, with reference to the accompanyingdrawings, in which:

FIG. 1 is an isometric view of the convertible hand truck in the uprightposition for use as a two wheeled dolly device;

FIG. 2 is a perspective view of the convertible hand truck in theplatform position for use as a four wheeled platform cart;

FIG. 3 is a back elevational view of the two wheeled dolly device shownin FIG. 1;

FIG. 4 is a side elevational view of the two wheeled dolly device shownin FIG. 1;

FIG. 5 is a top view of the four wheeled platform cart shown in FIG. 2;

FIG. 6 is a side elevational view of the four wheeled platform cartshown in FIG. 2;

FIG. 7 is a sectional view of the gravity operated pivot linkage takenalong line 55 on FIG. 2;

FIG. 8 is an enlarged elevational partial view of the spring operatedlocking mechanism shown in FIG. 3; and

FIG. 9 is a side elevational view of the spring operating lockingmechanism shown in FIG. 3.

DETAILED DESCRIPTION OF INVENTION The bulk hand truck provided by thisinvention and illustrated in the accompanying drawings includesgenerally an elongated frame 10 which defines a truck bed 11, handlegrips 12 at one end of the frame 10, a toe plate or lip 13 at the otherend of the frame 10, a pair of primary support wheels 14 at said otherend of the frame 10, a secondary handle 15 associated with the frame 10at said one end by virtue of a pair of gravity operated pivot linkages16, a pair of secondary support casters 17 carried by said secondaryhandle 15, and a pair of spring activated locking mechanisms 18associated with said secondary handle 15 to lock a secondary locking bar22 to the frame 10 and position the casters l7 flush with the frame 10when the hand truck is used in an upright dolly position.

The frame 10 is an elongate structure fabricated of steel, magnesium orsimilar material tubing, plate and angle stock. The various relatedparts going to make up the frame are secured or fixed together bywelding or any other well-known securing means to establish a unitary,integrated frame structure.

In the form of the invention illustrated, the frame 10 is provided witha pair of laterally spaced, elongate, parallel side members or rails 19,coextensive with the longitudinal extent of the frame 10, a handlesupport bar 20 fixed to and extending between the rails 19 andtransverse to the longitudinal axis of the frame 10, a pair of laterallyspaced axle brackets 41 fixed to the other end of the rail, and loadsupport members 21 fixed to and extending between the rails 19.

That portion of the frame 10 set forth above, that is, the primaryportion of the frame, defines an elongate,

flat, rectangular frame work having ends, sides and oppositely disposedplanes or surfaces. As illustrated in FIGS. 1, 3 and 4, when the portionof the frame now under consideration is vertically disposed and used asa two wheeled dolly device, it has upper and lower ends, parallel sidesand front and rear planes or surfaces. As illustrated in FIGS. 2, 5 and6, when it is horizontally disposed and used as a four wheeled platformcart, the front and rear planes as surfaces become upper and lowerplanes or surfaces and the upper and lower ends become front and rearends.

Referring to the drawing and more particularly FIGS. 1, 3 and 4, a bulkhand truck will be seen incorporating the present invention. The truckis diagrammatically illustrated in its standard upright two wheeledapplication. As depicted in FIG. 1, the truck or dolly device includes apair of spring activated locking mechanisms 18 for securing a secondaryhandle locking bar 22 to the rear of the hand truck bed 11 during theupright application and having a foot releasable lever 23 associatedtherewith so that upon being depressed by the user, the secondary handlelocking bar 22 is pushed free from the lock and rear of the hand truck,readying the hand truck for conversion to the platform application ofFIG. 2. The locking mechanisms 18 allow the secondary caster supportwheels 17 to be locked flush with the frame 10 when used in an uprightposition and in a location which does not interfere or otherwiseobstruct the user or product while the truck is used in the uprightposition.

As shown in FIGS. 8-9, each of the locking mechanisms 18 comprise a pairof upper 24 and lower 25 irregular shaped lock members that are mountedwithin flange means 27 which are in turn bolted or otherwise secured toopposite sides of frame 10. During an upright application of the truck,the secondary handle locking bar 22 is secured within the upper 24 andlower 25 lock members. Due to their irregular shapes, the upper section24 of each lock is positioned in an abutting relationship to lowersection 25 of the locking mechanisms 18 so that upon release of the footlever 23, the upper section 24 of each lock is rotated as shown in FIG.9 about axle 26. This rotation of upper sections 24 release lowersections 25 with the aid of tension springs 27 which raise the rear areaof lower sections 25 and push the locking bar 22 free from the lock andrear of the dolly device, readying the device for conversion to theplatform position.

In FIG. 7, a section is shown of one gravity operated pivot linkage 16that is provided between the secondary handle 15 and frame to enable auser to convert the hand truck from a standard upright two wheeledapplication to a four wheeled platform application in seconds. Each ofthe pivot linkages 16 comprise a sleeve 30 that is connected to theframe 10 of the truck by virtue of a pivot pin 31. The pivot pin 31 maybe bolted or secured between the handle and truck bed 11 by anywell-known means. A lock plate 32 is secured on opposite sides of theframe 10 at said one end of the frame to lock the truck in the platformposition. As the truck bed 11 slides down the secondary handle 15 into afinal horizontal position (See FIG. 2), the lock plates 32 secure thehandle 15 at the base portions (including locking bar 22) and preventfurther rotation or movement of the same. While in an upright position,a pair of locking flanges 35 function in conjunction with the lockingmechanisms 18 to lock the secondary handle and casters and preventfurther rotation thereof about pivot pins 31.

FIGS. 2, 5 and 6 illustrate the truck in a platform application. If itis desired to convert the truck from an upright position (FIG. 1) to aplatform position (FIG. 2), it is only necessary to use the followingsteps:

a. The spring-locked release bar 22 is tripped by the users foot freeingthe castered wheel end 17 of the secondary handle 15; and

b. With his free hand, user grasps the secondary handle 15, allowingplatform bed 11 and sleeve 30 to descend along the secondary handle-1Sand lock into the bottom of platform lock plates 32. Little externalforce is required to be exerted by the user since once the bar 22 isreleased, the truck center of gravity is changed so that the truckautomatically falls into the platform embodiment of FIG. 2.

In order to convert back to a two wheeled operation, the user merely hasto hold the platform cart at a location point 40 (FIG. 2) and reversethe above procedure. The above conversion procedures are unique in thatthey may be conducted with relative ease and without tools due to thetruck containing no loose parts.

From the foregoing, it will be apparent that I have provided a novel,highly versatile, effective and dependable utility truck constructionwhich is serviceable for moving and handling many different types and/orkinds of materials and goods.

It is believed that the present invention, its mode of construction,assembly and operation, and many of its advantages attendant theretoshould be readily understood from the foregoing without furtherdescription and it should also be manifest that, while a preferredembodiment of the invention has been shown and described forillustrative purposes, the structural details are nevertheless capableof wide variation within the purview of the invention as defined in theappended claims.

The embodiment of the invention in which an exclusive property right orprivilege is claimed are defined as follows:

1. A bulk hand truck capable of being adjustably positioned betweenfolded and unfolded positions to define either a two wheeled dollydevice or a four wheeled platform cart comprising an elongated framewith laterally spaced longitudinally extending side rails andlongitudinally spaced laterally extending load supporting members, saidframe defining head and base ends and upper and lower planes, a pair oflaterally spaced axle brackets fixed to and depending from the side'rails at the base end portion of the frame, an axle fixed to andextending between the brackets and rotatably supporting a pair ofprimary support wheels, an elongate toe plate fixed to the base end ofthe rails and the brackets to extend transverse of the base end of theframe and to project upwardly therefrom, an elongated U-shaped secondaryhandle having a pair of elongate parallel leg portions connectedtogether by virtue of a curved head portion and including a secondarysupport caster on the free end of each leg portion, means for slidably,as well as pivotally mounting the secondary handle to the head end ofsaid frame and allowing said secondary handle to be shifted from avertical, folded position parallel to the said rails to a horizontal,unfolded position transverse to the side rails.

2. A bulk hand truck as defined in claim 1 wherein locking means areprovided on the frame to releasably hold the secondary handle in itsvertical, folded position and parallel to the side rails of the truck.

3. A bulk hand truck as defined in claim 2 wherein the locking meanscomprise a pair of spring activated upper and lower lock members thatare positioned in abutting relationship to each other, connectedtogether by a tension spring and mounted to the frame whereby thesecondary handle may be secured by said lock members to the frame.

4. A bulk hand truck as defined in claim 1, wherein said means pivotallyconnecting the ends of'the secondary handle to the frame includes asleeve member on said leg portions of the secondary handle, said sleevemember being attached to the frame by laterally inwardly projectingpivot pins and said leg portions being slidable within said sleevemembers so as to shift the secondary handle from a folded verticalposition to an unfolded, horizontal position.

5. A bulk hand truck as defined in claim 4, wherein locking means areprovided on the frame to releasably hold the secondary handle in itsvertical, folded position and parallel to the side rails of the truck.

6. A bulk hand truck as defined in claim 5 wherein the locking meanscomprise a pair of spring activated upper and lower lock members thatare positioned adjacent to each other, connected together by a tensionspring and mounted to theframe whereby the secondary handle may besecured by said lock members to the frame.

7. A bulk hand truck as defined in claim 1, wherein a secondary handlelocking bar is fixed to and depending from the free ends of the legportions, locking means being provided on the frame to releasably holdthe secondary handle locking bar when the handle is positioned in itsvertical, folded position and parallel to the side rails of the truckand a manual releasable lever means being associated with the lockingmeans so that upon being depressed by a truck user, the secondary handlelocking bar is pushed free from the locking means, readying the truckfor conversion to the platform application.

8. A bulk hand truck as defined in claim 7, wherein said means pivotallyconnecting the ends of the secondary handle to the frame includes asleeve member on said leg portions of the secondary handle, said sleevemember being attached to the frame by laterally inwardly projectingpivot pins and said leg portions being slidable within said sleevemembers so as to shift the secondary handle from a folded verticalposition to an unfolded, horizontal position.

9. A bulk hand truck capable of being adjustably positioned betweenfolded and unfolded positions to define either a two wheeled dollydevice or a four wheeled platform cart comprising an elongated framewith laterally spaced longitudinally extending side rails andlongitudinally spaced laterally extending load supporting members, saidframe defining head and base ends and upper and lower planes, a pair oflaterally spaced axle brackets fixed to and depending from the siderails at the base end portion of the frame, an axle fixed to andextending between the brackets and rotatably supporting a pair ofprimary support wheels, an elongate toe plate fixed to the base end ofthe rails and the brackets to extend transverse of the base end of theframe and to project upwardly therefrom, an elongated U-shaped secondaryhandle having a pair of elongate parallel leg portions connectedtogether by a curved head portion and including a secondary supportcaster on the free end of each leg portion, means pivotally mounting theleg portions to the head end of said frame and including a sleeve memberslidably positioned on each of said leg portions and being attached tothe frame by a pair of laterally inwardly projecting pivot pins, a pairof spring activating first locking means being associated with the frameto releasably hold the secondary handle in a vertical, folded positionand parallel to the side rails of the truck when used as a two wheeleddolly device, a manually releasable lever means being affixed to saidfirst locking means so that upon being depressed, the secondary handleis pushed free from the first locking means, readying the truck forconversion to the four wheeled platform cart application.

10. A bulk hand truck as defined in claim 9 wherein a second lockingmeans are provided adjacent to the pivoting means at the head end of theframe and a secondary handle locking bar being fixed to and dependingfrom the free ends of the leg portions, said locking bar beingpositioned on the handle so as to cooperate with said first lockingmeans to secure the secondary handle parallel to the frame when thetruck is employed as a two wheeled dolly device and further positionedso as to cooperate with the second locking means to secure the secondaryhandle transverse to the frame when the truck is employed as a fourwheeled platform cart.

1. A bulk hand truck capable of being adjustably positioned betweenfolded and unfolded positions to define either a two wheeled dollydevice or a four wheeled platform cart comprising an elongated framewith laterally spaced longitudinally extending side rails andlongitudinally spaced laterally extending load supporting members, saidframe defining head and base ends and upper and lower planes, a pair oflaterally spaced axle brackets fixed to and depending from the siderails at the base end portion of the frame, an axle fixed to andextending between the brackets and rotatably supporting a pair ofprimary support wheels, an elongate toe plate fixed to the base end ofthe rails and the brackets to extend transverse of the base end of theframe and to project upwardly therefrom, an elongated U-shaped secondaryhandle having a pair of elongate parallel leg portions connectedtogether by virtue of a curved head portion and including a secondarysupport caster on the free end of each leg portion, means for slidably,as well as pivotally mounting the secondary handle to the head end ofsaid frame and allowing said secondary handle to be shifted from avertical, folded position parallel to the said rails to a horizontal,unfolded position transverse to the side rails.
 2. A bulk hand truck asdefined in claim 1 wherein locking means are provided on the frame toreleasably hold the secondary handle in its vertical, folded positionand parallel to the side rails of the truck.
 3. A bulk hand truck asdefined in claim 2 wherein the locking means comprise a pair of springactivated upper and lower lock members that are positioned in abuttingrelationship to each other, connected together by a tension spring andmounted to the frame whereby the secondary handle may be secured by saidlock members to the frame.
 4. A bulk hand truck as defined in claim 1,wherein said means pivotally connecting the ends of the secondary handleto the frame includes a sleeve member on said leg portions of thesecondary handle, said sleeve member being attached to the frame bylaterally inwardly projecting pivot pins and said leg portions beingslidable within said sleeve members so as to shift the secondary handlefrom a folded vertical position to an unfolded, horizontal position. 5.A bulk hand truck as defined in claim 4, wherein locking means areprovided on the frame to releasably hold the secondary handle in itsvertical, folded position and parallel to the side rails of the truck.6. A bulk hand truck as defined in claim 5 wherein the locking meanscomprise a pair of spring activated upper and lower lock members thatare positioned adjacent to each other, connected together by a tensionspring and mounted to the frame whereby the secondary handle may besecured by said lock members to the frame.
 7. A bulk hand truck asdefined in claim 1, wHerein a secondary handle locking bar is fixed toand depending from the free ends of the leg portions, locking meansbeing provided on the frame to releasably hold the secondary handlelocking bar when the handle is positioned in its vertical, foldedposition and parallel to the side rails of the truck and a manualreleasable lever means being associated with the locking means so thatupon being depressed by a truck user, the secondary handle locking baris pushed free from the locking means, readying the truck for conversionto the platform application.
 8. A bulk hand truck as defined in claim 7,wherein said means pivotally connecting the ends of the secondary handleto the frame includes a sleeve member on said leg portions of thesecondary handle, said sleeve member being attached to the frame bylaterally inwardly projecting pivot pins and said leg portions beingslidable within said sleeve members so as to shift the secondary handlefrom a folded vertical position to an unfolded, horizontal position. 9.A bulk hand truck capable of being adjustably positioned between foldedand unfolded positions to define either a two wheeled dolly device or afour wheeled platform cart comprising an elongated frame with laterallyspaced longitudinally extending side rails and longitudinally spacedlaterally extending load supporting members, said frame defining headand base ends and upper and lower planes, a pair of laterally spacedaxle brackets fixed to and depending from the side rails at the base endportion of the frame, an axle fixed to and extending between thebrackets and rotatably supporting a pair of primary support wheels, anelongate toe plate fixed to the base end of the rails and the bracketsto extend transverse of the base end of the frame and to projectupwardly therefrom, an elongated U-shaped secondary handle having a pairof elongate parallel leg portions connected together by a curved headportion and including a secondary support caster on the free end of eachleg portion, means pivotally mounting the leg portions to the head endof said frame and including a sleeve member slidably positioned on eachof said leg portions and being attached to the frame by a pair oflaterally inwardly projecting pivot pins, a pair of spring activatingfirst locking means being associated with the frame to releasably holdthe secondary handle in a vertical, folded position and parallel to theside rails of the truck when used as a two wheeled dolly device, amanually releasable lever means being affixed to said first lockingmeans so that upon being depressed, the secondary handle is pushed freefrom the first locking means, readying the truck for conversion to thefour wheeled platform cart application.
 10. A bulk hand truck as definedin claim 9 wherein a second locking means are provided adjacent to thepivoting means at the head end of the frame and a secondary handlelocking bar being fixed to and depending from the free ends of the legportions, said locking bar being positioned on the handle so as tocooperate with said first locking means to secure the secondary handleparallel to the frame when the truck is employed as a two wheeled dollydevice and further positioned so as to cooperate with the second lockingmeans to secure the secondary handle transverse to the frame when thetruck is employed as a four wheeled platform cart.